The invention relates to a dry-running piston rod sealing arrangement. The invention further relates to a method for the sealing of a piston rod having a dry-running piston rod sealing arrangement.
A dry-running piston rod sealing arrangement for a dry-running piston compressor having a longitudinally movable piston rod is known from the document EP 0933566 A1. This dry-running sealing arrangement includes sealing elements of a dry-running material such as carbon, graphite or plastic. The sealing element has a sealing surface which contacts the piston rod and forms a rubbing contact seal with respect to the piston rod in this way. This friction has the consequence of increasing wear of the sealing element; the sealing action of the sealing element is gradually reduced after a maximum permissible wear has been exceeded and the sealing element then has to be replaced relatively quickly. The friction of the sealing element on the piston rod moreover generates frictional heat which is difficult to dissipate, which has the consequence that the maximum pressure difference which can be sealed or the mean piston speed has to be restricted. The known piston rod sealing systems used for the oil-free sealing of gases, also termed a packing or dry-running sealing arrangement, are subjected to a high mechanical and thermal loading which has the disadvantageous consequence that the service life of the sealing elements, the maximum pressure difference which can be sealed and also the mean piston speed are restricted.